The following relates generally to wireless communication, and more specifically to sounding reference signal (SRS) triggering for enhanced carrier aggregation (eCA).
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems. A wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may each be referred to as a user equipment (UE).
A wireless communication system may support multiple component carriers (CCs) in a carrier aggregation (CA) or enhanced carrier aggregation (ECA or eCA) configuration. CCs may be configured for uplink (UL) and downlink (DL) communication between a base station and a UE. A UE may transmit reference signals (e.g., sounding reference signals (SRS)) to indicate the quality of a frequency channel used for communication with a base station. Other, unconfigured UL CCs could possibly be used for SRS transmissions, but aperiodic SRS transmissions are typically triggered with a grant of UL resources for data transmissions on the same CC as the SRS.